Heretofore, indium oxide conductive films have been made by a vacuum evaporation process wherein indium oxide is vacuum evaporated by electron beam heating or metallic indium is reactively evaporated in an oxygen atmosphere, or by a sputtering process wherein indium oxide is used as a target or a reactive sputtering is carried out in a gas including oxygen and using metallic indium as a target. However, indium oxide conductive films produced by these prior processes have a wide dispersion of values of measured resistances, and, therefore, it is very difficult to make films having a constant film resistance. Furthermore, most of them usually have higher values of resistance than desired. This tendency is particularly large when using metallic indium as a starting material. Accordingly, such a phenomenon has heretofore been a large obstacle to the production of indium oxide conductive films.